A component mounting line is provided with a screen printer which prints a paste such as solder on a substrate and a component mounting machine which mounts a component on the substrate on which the paste is printed by the screen printer. In the screen printer of such a component mounting line, a substrate clamped at the sides thereof by a pair of clamping members contacts with a lower surface of a mask having pattern holes formed thereon, a squeegee is slid on the mask contacted with the substrate to fill the pattern holes of the mask with a paste, and then the substrate is moved in a direction away from the mask to perform plate releasing (see Patent Document 1, for instance).
Patent Document 1 is JP-A-2003-266629.